ML350 G6 too too slow

I setup a ML350 G6 12GB Ram 4x146GB SAS Drives with two volumes with RAID 5.

The problem is the system speed, when you got the login screen and write down name and user it takes about 10 minutes to have the desktop available.

I run a disk benchmark test and got results below the 10MB/s both reading and writing.

I used the last firmware and flash for the array controller (from yesterday) and activate the cache with the array setup utility. The controller is as I bought it, without battery and no memory upgrade.

Re: ML350 G6 too too slow

Hi,

Yes I tried to boot first leaving just the hp services and no programs at all from start menu or registry "run". It was a little faster but not usable. After that I enabled the services from microsoft and the speed was almost the same.

Re: ML350 G6 too too slow

RAID 5 can do that. You never place the OS in RAID 5. Use RAID 1 or RAID 10 for the OS. Swap/Paging should be RAID 1 or 10 only. The 10 MB/s is caused by parity writes. I would consider backing up and redoing the server RAID configuration. I never use RAID 5 on production servers that need write performance. My servers and SAN use RAID 1 and RAID 10 only. RAID 5 is too slow for writes.

Re: ML350 G6 too too slow

I saw 10 MB/s per drive performance on RAID 5 on IOPS tests using IOMeter to similar SQL traffic 75% writes / 25% reads. Did you check your controller to verify battery cache is enabled and caching on the controller is enabled.

Re: ML350 G6 too too slow

The problem is RAID 5 parity writes. The controller has three functions: read, write, parity calculation. The problem with RAID 5 is parity calculations and writes. If your controller spends 70% writing data, it has to calculate parity for each of those writes for fault tolerance and redundancy. This can really slow down your arrays. This is how RAID 5 works. They did RAID 5 in the past because disks were slow and very expensive. Now with large inexpensive SAS drives, RAID 5 does not really make sense from a performance point of view.

I never use RAID 5 any more on production servers. It is too slow for writes. When you create or modify a file it is a write. Moving data from an old server to a new server with RAID 5 can be painful. I only use RAID 10 on production servers. If I need more space, I get a SAN and do RAID 10. I rather sacrifice about 5% read performance to gain write performance.

Re: ML350 G6 too too slow

Write cache can now be enabled on new gen smart array controllers without the battery requirement, it does however pose a risk of data loss upon power failure, however, for testing purposes I suggest you enable it (you will be warned of the risk of enabling it without a battery backup) and then if you wanna keep it for production, buy the battery backup.

Re: ML350 G6 too too slow

If you can, put another set of 4 disks on in RAID 10 and test performance. Crack open the server, check the battery is connected and it has a cache module. See what size the cache is. In the past, I upgraded 128 MB cache to 512 MB and saw a huge difference.

Re: ML350 G6 too too slow

I will open and check for the battery, the diagnostics utility saids it has 512MB of cache.

How can I upload the result file? I do select the file to upload and the file name appears next to the button, but when I push Submit, the screen goes blank and the message is not sent, if I go back the file is unselected and if push submit again the message is sent but without the attached file.

Re: ML350 G6 too too slow

You could backup the server and reconfigure the array as RAID 10 and test the performance. Other option is add four drives and test in RAID 10, if RAID 10 works better, move the data from four drive RAID 5 to RAID 10 and then create a second RAID 10 array from the RAID 5 drives.